Specification: Altimeter:Absolute sea level altitude measurement;Relative altitude measurement;Zero clearing function in relative altitude measurement;Maximum history altitude record;Sea level altitude setting directly Barometer:Range from 300 mbar to 1100mbar Digital Compass:4-bearing mode display;External magnetic field calibration;Magnetic declination setting;High accuracy, ±3 degrees Thermometer:Thermometer from -10 ℃ to 60 ℃(℃ or ℉ selectable) Weather forecast:The weather forecast for next 12 to 24 hours.4 weather status indicating, Sunny-Slight sunny- Cloudy-Rain Time:Time with hour, minute, second,24h format clock display Backlight:5 seconds super bright LED backlight Features: Compact in size, light in weight Material: Plastic Battery: CR2032 button batterySize: 63mm x 53mm x 15 mm / 25in x 2.1in x 0.6in (L x W x H) Care and Usage Notes: Altimeters are often misunderstood because they do not measure your actual position on the earth (true altitude) such as a GPS, but measure the air pressure and predict the altitude based on this measurement. This is referred to as "Pressure Altitude". Pressure Altitude is profoundly affected by the true altitude and to a lesser extent, changes in the weather, often referred to as barometric pressure changes. Thus, your Pressure Altitude can change without changing your position. These changes can be as great as a few hundred feet (the changes due to weather are more pronounced at higher altitude). To offset the difference between Pressure Altitude and True Altitude, you must calibrate the device at a known altitude, whenever convenient. Note: The item is water resistance: You could use it when it is raining, but you couldn"t put it into waterfor a long time. Package Include: 1x 6 in 1 multifunction altimeter 1x Clip-on carabineer 1x CR2032 button battery 1x English User manual